61728920 has 64 divisors (see below), whose sum is σ = 152409600. Its totient is φ = 22314880.

The previous prime is 61728917. The next prime is 61728959. The reversal of 61728920 is 2982716.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 104867 + ... + 105453.

It is an arithmetic number, because the mean of its divisors is an integer number (2381400).

Almost surely, 2^61728920 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61728920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76204800).

61728920 is an abundant number, since it is smaller than the sum of its proper divisors (90680680).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61728920 is a wasteful number, since it uses less digits than its factorization.

61728920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 848 (or 844 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 61728920 is about 7856.7754199799. The cubic root of 61728920 is about 395.2114874520.

The spelling of 61728920 in words is "sixty-one million, seven hundred twenty-eight thousand, nine hundred twenty".